layui.use(['jquery'], function() { 
    let $ = layui.jquery;

    $(document).on("click", ".layui-nav-child a", function() { 
        let that = $(this);
        $("a", that.parent().parent()).each(function() { 
            $(this).parent().removeClass("layui-this");
        });
        //that.parent().addClass("layui-this");
    });
});
